Abstract:
Over the course of 3 hr on 2008 December 27, we obtained optical (R band) observations of the blazar S5 0716+714
at a very fast cadence of 10 s. Using several different techniques, we find fluctuations with an approximately 15
minute quasi-period to be present in the first portion of these data at a >3σ confidence level. This is the fastest
quasi-periodic oscillation that has been claimed to be observed in any blazar at any wavelength. While these data
are insufficient to strongly constrain models for such fluctuations, the presence of such a short timescale when the
source is not in a very low state seems to favor the action of turbulence behind a shock in the blazar’s relativistic jet.
